Spreading mormon lies I see. The verse you quote is talking about self washed persons who have not been washed by the Holy Spirit. They were never saved. Peter most definitely affirms that once God has saved a saint, that they will be preserved forever:
Peter, an apostle of Jesus Christ, To the strangers scattered throughout Pontus, Galatia, Cappadocia, Asia, and Bithynia, elect according to the foreknowledge of God the Father through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you and peace be multiplied.For the LORD loveth judgment, and forsaketh not His saints; they are preserved for ever, but the seed of the wicked shall be cut off.Blessed be the God and Father of our Lord Jesus Christ, who according to His abundant mercy hath begotten us again unto a living hope by the resurrection of Jesus Christ from the dead, to an inheritance incorruptible and undefiled and that fadeth not away, reserved in Heaven for you, who are kept by the power of God through faith for salvation ready to be revealed in the last time.
The Lord is not slack concerning His promise, as some men count slackness, but is longsuffering toward us, not willing that any should perish, but that all should come to repentance.
Where in the scriptures does the phrase "self washed persons" occur? Just trying to understand where this phrase comes from.
Does this mean that since God wills that not any should perish, none will perish?
Just because God's will is that certain things should happen doesn't mean that they will happen. God will never override a person's free agency to choose evil over good if it is that person's choice. If a person chooses to not be saved, God is not going to force that person into heaven. You may be one of the elect, but you can always choose to become un-elect.
Otherwise there'd be no point in God exhorting us to "endure to the end".